Acorus gramineus 'Minimus Aureus'

A number of cultivated varieties of Grass Sweet Flag (Acorus gramineus) from East and Southeast Asia are available, differing in height and leaf colour. 'Minimus Aureus' is similar to the dwarf form, A. gramineus 'Pusillus', but has bright yellow-green leaves. Golden Dwarf Sweet Flag grows to around 10–15 cm tall.
The wild form of Grass Sweet Flag occurs, among other habitats, along fast-flowing, rocky forest streams and waterfalls, where it grows in gravel or attached to rocks. During periods of high water, it becomes submerged and is exposed to strong currents.

Grass Sweet Flag is often regarded as being only of limited suitability for aquariums. However, we have found that at least the dwarf cultivar, Acorus gramineus 'Pusillus', can grow permanently submerged. The key is not to bury the rhizome, as this may cause the plant to die. Instead, it should be tied to rocks or wood, or otherwise attached to hardscape, in the same way as Anubias species or Java Fern. The roots will naturally anchor themselves to hard surfaces. Growth is very slow, and the rhizome gradually produces side shoots that can be separated for propagation. We recommend a complete supply of macro- and micronutrients via the water column, CO₂ supplementation, and good water movement. Moderate lighting is sufficient. Dwarf Sweet Flag prefers cooler conditions, with an optimum temperature range of 18–23 °C.
The dwarf cultivars are also very easy to grow as terrestrial plants. The substrate, such as ordinary potting compost, only needs to be kept evenly moist rather than wet. The plants can also be overwintered in cool, frost-free conditions.

This attractive, grass-like plant is suitable for both tropical and coldwater aquariums. However, successful long-term submerged cultivation depends on keeping the rhizome above the substrate, as described above. Its use as an epiphyte on rocks or wood is still little known but well worth trying. Dwarf Sweet Flag is also highly versatile as a hardy terrestrial plant in paludariums, ripariums, terrariums and Wabi-Kusa. With its striking yellow-green foliage, the cultivar 'Minimus Aureus' provides an attractive accent.